Precursors and pathfinders

Precursor facilities

Precursor telescopes like the South African MeerKAT and HERA, along with the Murchison Widefield Array (MWA) and CSIRO’s Australian SKA Pathfinder (ASKAP) are providing SKA scientists with invaluable knowledge to assist in the design of the SKA’s main telescopes over the coming decade.

Located at future SKA sites, these precursors are and will be in future carrying out scientific study related to future SKA activities, as well as helping the development and testing of new crucial SKA technologies.

The Murchison Widefield Array

The Murchison Widefield Array, shown in the above image is just one of the many telescopes contributing to the final SKA in terms of scientific and technical input.

MeerKAT, which is currently taking shape in South Africa’s Karoo region, will be a world-class radio telescope array in its own right and is designed to do ground-breaking science ahead of the SKA becoming operational in the early 2020s. Until that time, it will be the largest and most sensitive radio telescope in the Southern Hemisphere. MeerKAT itself will also form part of the main SKA array.

HERA, which is also under construction at the South African site, will consist of an array of up to 350 14m diameter parabolas studying the Universe between 50-250MHz. As such HERA will be a precursor of SKA-low, the low-frequency part of the SKA, to be built in Australia from 2018 onwards.

Photo of the first 19 elements of HERA on the SKA-SA site.

Both ASKAP and MeerKAT will be operating ahead of the full SKA system coming online, and MeerKAT will integrate into phase one of the SKA, which will be building on their unique science capabilities and scientific output.

Image of ASKAP (on the left) and MeerKAT (on the right) antennas.

ASKAP in Australia is also performing cutting edge scientific work ahead of the deployment of the huge swath of wide field low frequency antenna which Australia will host as part of the SKA. The 36 antennas which form ASKAP are already installed at the Murchison Radio Observatory (MRO) site in Western Australia.

These are currently being equipped with their precision electronics designed to test many of the concepts which will apply to the SKA. Once the commissioning phase completed, ASKAP will start its first science observations and will provide world-class science as a foretaste of the future.

Pathfinders

Pathfinder telescopes and systems, dotted around the globe are also engaged in SKA related technology and science studies. These include the famous Arecibo radio telescope in Puerto Rico, which starred in the James Bond movie “Goldeneye”, the LOFAR low-frequency array, which is based in Europe, and the EVLA, in North America, which was famously seen in the hit movie “Contact”. Here is a list of SKA Pathfinders;

Applying for designation

In 2008, the SKA Science and Engineering Committee (“SSEC”) recognised that there had been a proliferation of self-declared “SKA Pathfinders” and that a clear definition of what constitutes a Pathfinder facility was necessary to protect the SKA brand name. Therefore, the following designations were established:

Precursor facility: A telescope on one of the two candidate sites

Pathfinder: SKA-related technology, science and operations activity

To apply for a designation, an “SKA Contribution” must satisfy one or more of the following criteria in the areas of technology, science and operations:

it contains new technical elements that have not been tried before on the scale of a large telescope and which are part of the SKA Baseline Design – technology;

it will carry out observational tests, both simulated and real, that explore new capabilities at flux density and dynamic range levels similar to or scalable to the full SKA – science;

it tests methods of scheduling and allocating time similar, or scalable to, that needed for the SKA – operations.

Applications for an SKA designation should be sent to the Director-General of SKA Organisation and must include the following: (i) demonstration of a clearly defined path for the results of the activity to reach, and potentially influence, the international SKA project, and (ii) the name and email address of the primary contact for the facility. In order for a facility to be awarded an SKA designation, there must be a mechanism in place for communicating results on an on-going basis to the Office of SKA Organisation.

The Director-General is the sole arbiter of what constitutes a Precursor or Pathfinder.

Further information about SKA precursors and pathfinders can be obtained from Colin Greenwood, Company Secretary.